Voice coil motor

ABSTRACT

A voice coil motor includes a base, a housing, a lower-resilient member, a lens frame, a coil, a magnet, an upper-resilient member, an upper cover plate, and a pin arranged on the base. The lower-resilient member, the lens frame, the coil, the magnet, the upper-resilient member, and the upper cover plate are arranged in sequence between the base and the housing. The lens frame and the coil are integrally formed. The coil surrounds an outer surface of the lens frame.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application of patent application Ser. No.16/122,980, filed on Sep. 6, 2018, assigned to the same assignee, whichis based on and claims priority to China Patent Application No.201810892810.0 filed on Aug. 7, 2018, the contents of which areincorporated by reference herein.

FIELD

The subject matter herein generally relates to voice coil motors, andmore particularly to a voice coil motor having a coil integrally formedwith a lens frame.

BACKGROUND

Voice coil motors are used in electronic devices, such as digitalcameras and mobile phones, to drive motion within the electronic device.As electronic devices become smaller, voice coil motors need to be madesmaller. However, as voice coil motors become smaller, a lens frame ofthe voice coil motor becomes more fragile.

Therefore, there is room for improvement within the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present disclosure will now be described, by wayof example only, with reference to the attached figures.

FIG. 1 is an assembled, isometric view of an embodiment of a voice coilmotor of the present disclosure.

FIG. 2 is an exploded, isometric view of the voice coil motor in FIG. 1.

FIG. 3 is similar to FIG. 2, but showing the voice coil motor fromanother perspective.

FIG. 4 is a cross-sectional view of the voice coil motor in FIG. 1 takenalong line IV-IV.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements.Additionally, numerous specific details are set forth in order toprovide a thorough understanding of the embodiments described herein.However, it will be understood by those of ordinary skill in the artthat the embodiments described herein can be practiced without thesespecific details. In other instances, methods, procedures and componentshave not been described in detail so as not to obscure the relatedrelevant feature being described. The drawings are not necessarily toscale and the proportions of certain parts may be exaggerated to bettershow details and features. The description is not to be considered aslimiting the scope of the embodiments described herein.

Several definitions that apply throughout this disclosure will now bepresented.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“substantially” is defined to be essentially conforming to theparticular dimension, shape, or other word that “substantially”modifies, such that the component need not be exact. For example,“substantially cylindrical” means that the object resembles a cylinder,but can have one or more deviations from a true cylinder. The term“comprising” means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in aso-described combination, group, series and the like.

FIGS. 1-4 show an embodiment of a voice coil motor 100. The voice coilmotor 100 includes a base 10, a housing 20, a lower-resilient member 30,a lens frame 40, a coil 50, a magnet 60, an upper-resilient piece 70, anupper cover plate 80, and pins 90.

FIG. 2 shows the base 10 is substantially rectangular. A central portionof the base 10 defines a light hole 101. The light hole 101 allows lightto pass through to allow an image sensor (not shown) situated below thebase 10 to receive the light for forming the image. The base 10 includesa sidewall 12 and an outer flange 14 coupled to an outer side of thesidewall 12. The sidewall 12 includes four perpendicularlyinterconnected sidewall surfaces 120. The outer flange 14 extendsperpendicularly from the sidewall surface 120.

The outer flange 14 of the base 10 includes an upper end surface 140perpendicular to each sidewall surface 120. The upper end surface 140 isconcavely recessed at a central area of each sidewall surface 120. Thus,the outer flange 14 defines a concave portion 142. The concave portion142 includes a step surface 144 parallel to the upper end surface 140.

The sidewall surface 120 has a first strengthening piece 16 formedthereon. The step surface 144 has a second strengthening piece 18 formedthereon. The first and second strengthening pieces can be made of metal.

In an embodiment, the first strengthening piece 16 and the secondstrengthening piece 18 are integrally formed with the sidewall surface120 and the step surface 144, respectively, by insert molding. When thebase 10 is formed by insert molding, the first strengthening piece 16and the second strengthening piece 18 are embedded in the base 10. Thefirst strengthening piece 16 and the second strengthening piece 18strengthen the base 10.

The base 10 further includes an upper surface 103 perpendicular to eachsidewall surface 120. The upper surface 103 includes guiding projections110 protruding therefrom. The lower-resilient piece 30 is arranged onthe guiding projections 110.

One side of the guiding projections 110 defines two through holes 105.The two through holes 105 receive the pins 90. The pins 90 areconfigured to be electrically coupled to an external circuit board.

The housing 20 is made of metal, such as iron. The housing 20 made ofmetal is able to reduce external electromagnetic interference of thevoice coil motor 100 and prevent the voice coil motor 100 fromelectromagnetically interfering with the operation of externalelectronic components thereof. The housing 20 includes a top wall 22 anda side wall 24 perpendicularly extending from a periphery of the topwall 22. The top wall 22 defines a light transmission hole 220. The topwall 22 and the side wall 24 cooperatively define an accommodating space201 to accommodate therein the lower-resilient piece 30, the lens frame40, the coil 50, the magnet 60, the upper-resilient member 70, and theupper cover plate 80. A lower end 240 of the side wall 24 away from thetop wall 22 defines a notch 242.

In one embodiment, the housing 20 is substantially rectangular. The sidewall 24 includes four perpendicularly interconnected sides 244. Eachside 244 defines at least one notch 242.

In one embodiment, each side 244 defines two spaced apart notches 242.

The housing 20 further includes a plurality of connecting pieces 26. Inat least one embodiment, a shape of each connecting piece 26 matches ashape of a corresponding corner of the housing 20. Each connecting piece26 extends from the top wall 22, through the light transmission hole220, and toward the base 10, and each connecting piece 26 is situated ina corresponding corner of the housing 20.

When the housing 20 is arranged on the base 10, the notches 242 reveal aportion of the first strengthening piece 16 and a portion of the secondstrengthening piece 18. The revealed portions of the first strengtheningpiece 16 and the second strengthening piece 18 have soldering zones 210formed thereon. A laser or solder are used to solder the soldering zones210 to attach the base 10 and the housing 20 together, so that thehousing 20 and the base 10 do not separate from each other. Aftersoldering the soldering zone 210, the voice coil motor 100 is turnedover to face the base 10 upwards, and an adhesive is provided on thevoice coil motor 100. The adhesive flows into spaces in between the base10 and the housing 20 to further strengthen attachment of the base 10and the housing 20.

The lower-resilient piece 30, the lens frame 40, the coil 50, the magnet60, the upper-resilient piece 70, and the upper cover plate 80 are allreceived within the accommodating space 201.

The lower-resilient piece 30 is fixed onto the guiding projections 110of the base 10.

FIG. 2 shows the lens frame 40 includes an annular step 41 surroundingan outer surface of the lens frame 40. FIG. 3 shows a bottom surface 401of the lens frame 40 includes two fixing columns 42.

The coil 50 is formed around the outer surface of the lens frame 40. Thecoil 50 includes a coil body 51 and a first winding portion 53 and asecond winding portion 55 coupled to the coil body 51. The first windingportion 53 and the second winding portion 55 are respectively sleeved ona corresponding one of the fixing columns 42 to fix the coil 50 to thelens frame 40.

FIG. 4 shows the coil 50 is integrally formed onto an outer surface ofthe lens frame 40 by insert molding embedding the coil 50 in the frame.

Integrally forming the lens frame 40 with the coil 50 helps to stabilizea torsion force of the lens frame 40 to reduce risk of deformation ofthe lens frame 40. Additionally, integrally forming the coil 50 with thelens frame 40 helps to prevent a head end and tail end of the coil 50from exposing and fraying copper wire of the coil 50. Furthermore,integrally forming the lens frame 40 with the coil 50 reduces athickness of the lens frame 40, and a size of the voice coil motor 100is reduced.

The magnet 60 includes a plurality of individual magnets arranged aroundthe coil 50. In one embodiment there are 4 magnets 60, one magnet foreach side of coil 50. The upper cover plate 80 is substantiallyrectangular. The upper-resilient piece 70 is fixed between the uppercover plate 80 and an upper surface of the lens frame 40.

The coil 50 conducts a current to generate magnetic induction with themagnets 60 to cause the coil 50 to move relative to the magnets 60. Thelens frame 40 and the coil 50 serve as a moving part. The magnets 60drive the lens module to move up and down to optically focus the lensmodule.

When the voice coil motor 100 is in use, the lens module is installedwithin the lens frame 40. The voice coil motor 100 is installed on acircuit board having an image sensor so that the light transmission hole220 faces the image sensor. The voice coil motor 100 is used to drivethe lens module to move up and down to adjust focus.

A method of making the voice coil motor 100 includes the followingsteps.

At step S1, coil 50 is provided.

At step S2, the coil 50 is placed within an injection mold of the lensframe 40, and the lens frame 40 is formed in the injection mold.Therefore, the coil 50 is directly fixed on an outer surface of the lensframe 40.

At step S3, four first strengthening pieces 16 and four secondstrengthening pieces 18 are placed within an injection mold of the base10. The base 10 is formed in the injection mold, and the firststrengthening piece 16 and the second strengthening piece 18 areintegrally formed on the sidewall surface 120 and the step surface 144,respectively, of the base 10.

At step S4, two pins 90 are placed within the base 10.

At step S5, the base 10, the lower-resilient member 30, the lens frame40, the magnets 60, the upper-resilient member 70, and the upper coverplate 80 are stacked on top of each other in sequence between thehousing 20 and the base 10.

At step S6, a laser or solder is used on the soldering zone 210 of thebase 10 and the housing 20 to solder the base 10 and the housing 20,thereby preventing the housing 20 from separating from the base 10.

In detail, when the housing 20 is attached to the base 10, a portion ofthe first strengthening piece 16 and a portion of the secondstrengthening piece 18 are revealed. The revealed portions of the firststrengthening piece 16 and the second strengthening piece 18 have formedthereon the soldering zone 210. A laser or solder are used on thesoldering zones 210 to solder the soldering zones 210 to fix the base 10and the housing 20 together.

At step S7, after the soldering zones 210 are soldered, adhesive isapplied between the base 10 and the housing 20. The adhesive flows intospaces between the base 10 and the housing 20 to fix the base 10 and thehousing 20. Thus, the base 10 and the housing 20 coupled together arestrengthened.

The voice coil motor 100 as described above uses the lens frame 40integrally formed with the coil 50. The lens frame 40 integrally formedwith the coil 50 helps to stabilize a torsion force of the lens frame 40to reduce risk of deformation of the lens frame 40. In addition, thecoil 50 integrally formed with the lens frame 40 helps to prevent a headend and tail end of the coil 50 from exposing and fraying copper wire ofthe coil 50. Furthermore, the lens frame 40 integrally formed with thecoil 50 reduces a thickness of the lens frame 40, and a size of thevoice coil motor 100 is reduced.

The embodiments shown and described above are only examples. Even thoughnumerous characteristics and advantages of the present technology havebeen set forth in the foregoing description, together with details ofthe structure and function of the present disclosure, the disclosure isillustrative only, and changes may be made in the detail, including inmatters of shape, size and arrangement of the parts within theprinciples of the present disclosure up to, and including, the fullextent established by the broad general meaning of the terms used in theclaims.

What is claimed is:
 1. A voice coil motor comprising: a base; a housing;a lower-resilient member; a lens frame; a coil; a magnet; anupper-resilient member; an upper cover plate; and a pin arranged on thebase; wherein: the lower-resilient member, the lens frame, the coil, themagnet, the upper-resilient member, and the upper cover plate arearranged in sequence between the base and the housing; the lens frameand the coil are integrally formed; and the coil is embedded on andsurrounds an outer surface of the lens frame.
 2. The voice coil motor ofclaim 1, wherein the lens frame and the coil are formed by injectionmolding.
 3. The voice coil motor of claim 1, wherein the base comprisesa sidewall comprising a first strengthening piece fixed thereon; thehousing comprises a top wall and a side wall perpendicularly extendingfrom a periphery of the top wall; the side wall defines a notch; thehousing is arranged on the base; the notch reveals a portion of thefirst strengthening piece forming a soldering zone.
 4. The voice coilmotor of claim 3, wherein the base and the housing are fixed together byspot-soldering the soldering zone.
 5. The voice coil motor of claim 3,wherein a central portion of the base defines a light hole; the sidewallcomprises four perpendicularly interconnected wall surfaces; each of thewall surfaces has formed thereon a corresponding one of the firststrengthening piece.
 6. The voice motor of claim 3, wherein the basefurther comprises an outer flange extending perpendicularly from asidewall surface of the sidewall, the outer flange defines a concaveportion having a second strengthening piece fixed thereon, the notchfurther reveals a portion of the second strengthening piece to form thesoldering zone.
 7. The voice motor of claim 6, wherein the firststrengthening piece and the second strengthening piece are embedded inthe base.
 8. The voice coil motor of claim 3, wherein the top walldefines a light transmission hole, the housing further comprising aplurality of connecting pieces, a shape of each of the plurality ofconnecting pieces matches a shape of a corresponding corner of thehousing, each of the plurality of connecting pieces extends from the topwall, through the light transmission hole, and toward the base, and issituated in a corresponding corner of the housing.
 9. The voice coilmotor of claim 1, wherein the upper-resilient piece is fixed between theupper cover plate and an upper surface of the lens frame, thelower-resilient piece is fixed onto guiding projections protruding froman upper surface of the base.
 10. The voice coil motor of claim 1,further comprising an adhesive infilling space between the base and thehousing.